Dental apparatus with enhanced handpiece manipulability

ABSTRACT

Structure is provided for a dental handpiece comprising an operating instrumentality driven to perform dental operations within the oral cavity. The handpiece is of the air rotor type and hose means delivering air and water to the operating instrumentality is comprised of a flaccid material for an unsupported portion of its length between the handpiece and an adjustable supporting element through which the major portion of the air-water hosing extends. The adjustable supporting element enables placement of the handpiece proximate a working location while supporting the major portion of the hosing length. The flaccid hose portion in combination with the adjustable supporting element enables manipulation of the handpiece with elimination of much of the torque and drag normally encountered. By a second aspect of the invention, a weight is adjustably mounted within the handpiece to enable achievement of a balanced feel to suit the individual choice of an operator, as well as precise manipulation and control.

Unie States Patent 1191 Graysnn e at 111] $726,012 1'45] Apr. 111, 1973 DENTAL APPARATUS :1 1",;

HANDPIECE [76]- Inventors: Barry H. Grayson; Allan S. Grayson, both of 334 East 25th St.,

NewrYork NX. 10010 [22] Filed: Apr. 5, 1971 [21 Appl. Nol: 130,986

[52] us. c1. ..32/22 [51] 1111.0 ..A6lc 19/02 [58]- FieldofSearch ..32/26,27,22,2'3, I 3205,29

[56] 1 References Cited UNITED STATES PATENTS 1,313,031 8/1919 Gildardo ..32/22X 3,160,379 12/196 Gardella ..V.32/22x Primary Examinep-Robert Peshock Attorney-Hubbell, Cohen & Stiefel [57] ABSTRACT Structure is provided for a dental handpiece comprising an operating instrumentality driven to perform dental operations within the oral cavity. The handpiece is of the air rotor type and. hose means delivering air and water to the operating instrumentality is comprised of a flaccid material for an unsupported portion of its length between the handpiece and an adjustable' supporting element through which the major portion of the air-water hosing extends. The adjustable supporting element enables placement of the handpiece proximate a working location while supporting the major portion of the hosing; length. The flaccid hose, portion in combination with the adjustable supporting element enables manipulation of the handpiece with elimination of much of the torque and drag normally encountered. By a second aspect of the invention, a weight isadjustably mounted within the handpiece to enable achievement of a balanced feel to suit the individual choice of an operator, as well as precise manipulation and control.

21 Claims, 16 Drawing Figures 'PATEMEUW 0 ms SHEET 2 0F 3 mam Jill-mulling IIIIIIIIIIIIIllllllll)llilill;;l)lllIII! .I 15f mvmons BARRY H.GRAYSON BY ALLAN S.GRAYSON f1 ATTORNEY PATEH'iE-QAFR 1 01m 3' 5,0 1 2 sum 3 OF 3 INVENTORS BARRY H. GRAYSON BY ALLAN s. GRAYSON ATTORNE DENTAL APPARATUS WITH ENHANCED HANDPIECE MANI PULABILITY BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to dental apparatus and more particularly to the structure and arrangement of an assembly for a dental handpiece including an operating instrumentality which is powered by an air rotor in the performance of dental operations within an oral cavity. More specifically, the invention conteming air and water to power and cool the operating in-.

strumentality or drill of the handpiece. in this type of device, air is applied todrive the rotor of the operating instrumentality,'and water 'is applied to cool the teeth during the dental operation. This type apparatus requires separate hosing for the air and the water, and it has been found that the weight and rigidity of the hosing will produce significant resistive force during manipulative operation of the handpiece. In air rotor plates an arrangement whereby the handpiece may be I thereof. Power means such as .belt driven pulley systems have been utilized to extend to the handpiece in supplying power to drive the drill during dental operations. Since the area within the oral cavity where work must be performed is generally quite sensitive and involves close spacing, great care and accuracy on the part of a dental operator is required.

However, accurate control and manipulation of the handpiece is quite often adversely affected by forces imparted thereto through the mechanisms which are provided to power the operating instrumentality. For example, in prior art dental devices in which the operating instrumentality or drill is driven by a belt and pulley arrangement, significant drag is imparted to the handpiece by the sheer weight of the pulley system which must be moved. Such imparted drag increases the difficulty encountered by the operator in attempting to delicately and carefully control the movement of the handpiece.

Clearly, therefore, it would be advantageous to structure such a dental handpiece system in a manner whereby imparted forces detracting from precise con trol and manipulation of the handpiece could be eliminated or minimized. Also, the feel or balance of a handpiece involves a significant factor, sincea good deal of discomfort may be experienced depending upon individualized requirements of particular operators. As in any manipulable tool or device, the ability to individualize the feel or balance of a device will afford significant advantage in providing operator comfort as well as to enhance delicacy of control. Clearly, achievement ofindividualized balance and comfort in a handpiece would be rendered of little benefit if forces imparted to the handpiece bythe driving mechanism were to destroy the balanced feel created.

In prior art devices, easing of the forces imparted to a handpiece has been attempted by introduction of new or improved flexible pulley systems for driving the operating instrumentality of the handpiece, but nevertheless certain deficiencies inherent in this type of apparatus have endured. Bulkiness, inefficiency and a lack of aestheticism are concom mitant features of almost all mechanical pulley systems.

The advent of the air rotor handpiece in dentalapparatus brought about utilization of hosing for delivertype equipment, the weight of the hosing which isutilized introduces. drag upon the handpiece and the rigidity of the material introduces torque, thereby reducing mobility and control and obviating much of any advantage which could be derived from a well designed, comfortably balanced handpiece.

ln presently known priorart approaches, one expedient which has been utilized is to arrange the equipment, particularly the floor console which houses most of the operative elements of the apparatus, as close as possible to thepatient in an attempt to minimize th length of free unsupported hosing. This may be effective to a limited extent but it will introduce other disadvantages, such asencroachmentof the equipment console upon the working space of the operator, or encumbrance of the patient. l

Accordingly, it will bev apparent that equipment which enables minimization or elimination of drag and torque forces created by theweight and rigidity of fluid transmitting hosing in air rotor types of dental equipment, without requiring encroachment upon the working space of an operator or encumbrance of the patient, will involve significant advantages for several reasons,

including provision of the opportunity to ad vantageou'sly utilize a handpiece of superior design and balance.

SUMMARY OF THE INVENTION Briefly,- the present invention maybe described as dental apparatus comprising a handpiece including an operating instrumentality manipulable for location relative to an oral cavity, a'source of fluid supply, hose means extending between said fluid source and said handpiece for transmittingfluid to effect operation of saidoperating instrumentality, said hose means comprising a flaccid portion adjacent said handpiece rendering said hose means substantially ineffectual to impart resistive torque to said handpiece during manipulation thereof, and adjustable support means for said hose means enabling selective supported positioning thereof relative to said oral cavity, said support means being operably unconnected withsaid hand piece and terminating support of said hose means at a distance therefrom to leave unsupported said flaccid hose means portion between saidsupport means and said handpiece.

By a more specific aspect of the present invention,

the weight and thehandpiecemay comprise gear BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the present invention may be had by reference to the following detailed description of preferred embodiments thereof taken in connection with the accompanying drawings wherein:

FIG. 1 is a side elevational view of dental apparatus embodying the present invention and showing a dental chair and an appurtenant console with related equip ment; I

FIG. 1A is a side elevational view ofa console similar to that shown in FIG. 1 showing an alternative for the adjustable support means of the invention;

FIG. 1B is a side elevational view showing a dental chair similar to that shown in FIG. I wherein the equipment console is mounted upon the back of the chair;

FIG. 1C is a sectional view taken along the line 1C 1C in FIG. 1;

FIG. 2 is a fragmentary longitudinal view depicting a typical dental handpiece in accordancev with the present invention: I

FIG. 3 is a fragmentary longitudinal sectional view of the handpiece of FIG. 2;

FIG. 4 is a cross sectional view taken along the line 44 of FIG. 3;

FIG. 5 is a cross sectional view taken along the line 5-5 ofFIG. 3;

FIG. 6 is a fragmentary longitudinal sectional view depicting a second embodiment of a handpiece made in accordance with the present invention;

FIG. 7 is a cross sectional view taken along the line 7--7 of FIG. 6;

FIG. 8 is a cross sectional view taken along the line 8-8 of FIG. 6;

FIG. 9 is afragmentary longitudinal view depicting DETAILED DESCRIPTION OF THE PREFERRED I EMBODIMENTS Referring nowv in detail to the drawings, there is shown in FIGfl dental apparatus embodying the ele men'ts of the present invention and including a dentist's chair 10 having located in proximity thereto a console member 12 comprising a table portion 13, with the I an alternative embodiment of the handpiece of the in- I hose means 20 is operably interconnected in flow rela-' combined structure having mounted therein equipment normally useful in the performance of ordinary dental operations. Thus, the table portion 13 will contain thereupon much of the ordinary apparatus which is utilized to provide a more commodious environment for the patient. while at the same time being internally structured to house and support other equipment suchas the mechanical, electrical, hydraulic or pneumatic elements required in powering arid operating the apparatus. Since the present invention is particularly adaptable for utilization in connection with air rotor typesof dental equipment, it is intended that the console 12 contain sources of air and water which are applied, in a manner to be further discussed hereinafter, in the operation of the dental equipment involved. The particular structure and arrangement of the console, as well as the nature and configuration of the power equipment including the sources of air and water, are

' not shown in detail and may be configured in ac-- corclance with conventional prior art arrangements. The present invention is considered adaptable and usable with a variety of such types of equipment and a detailed description of this portion of the operative structure is not considered necessary to a full understanding of the nature and operation of the inventron.

The basic elements of the present invention are embodied in adjustable support means comprised of a flexible jointed metal pipe or gooseneck 16, a dental handpiece 18, and a flaccid hose portion 20 extending between the gooseneck 16 and the handpiece 18. These elements cooperate, in a manner to be more fully described, to provide the benefits of the invention. A clip mount 22, which is not an essential feature of the invention, may be provided at the end of the gooseneck 16 in order to provide a repository for the handpiece 18 when not in use. Although gooseneck 16 is presently preferred other types of self supporting multi-positional supporting arms may be employed within this invention. Further, if desired the multi-positional supporting arm may be arranged to be retractable into table 13 (or unit 34 of FIG. 1b) without departing from this inventio'n.

I The handpiece 18, shown in somewhat greater detail in FIG. 2, comprises a rotor 24 which is located at the operating end thereof and which includes theusual operating instrumentality such as a bur 26 or other similar device adapted to perform dental operationsv within an oral cavity. The operating instrumentality 26 is powered through the rotor 24 by means of air directed through the flaccid hose portion 20 which is configured as two separate flaccid circular hoses 20a and 20b, with one of the hoses supplying air to drive the rotor 24 and with the other of said hoses supplying water for cooling the operating instrumentality 26 dur-- ing operation of the device. The structure and operationof the rotor end 24 of the handpiece 18' may be conventional and in accordance with known principles.

It should be understood that the portion of flaccid detracts from or limits the manipulability of the hand- I piece 18 will produce significant detriment in the functioning of the apparatus In prior art devices of the air rotor type, the hosing necessary to provide air and water has been such as to cause drag and torque upon the handpiece during operation. Usually, the length of the hose which must extend between the source of air and water, i.-e., the console 12, and the handpiece 1% involves a weight which creates drag upon the handpiece 18 thereby reducing comfort and manuverability when the dentist is working within the oral cavity and when he is required to move to different positions in an around the dental chair. Shortening the length of hose to overcome this detriment would require that the console 12 be brought uncomfortably close, to the chair drag upon thehandpiece thereby adding to the difficultyencountered by the dentist in adequately controlling and manipulating the handpiece. t I

Additionally, the materials used in forming prior art phasin 'a rarsirfncieht rigidity that the operator is caused to experience torque forces when twisting or rotating the handpiece during use. l I, x The present invention is'airned toward alleviating these drag and torque forces. Basically, the'invention accomplishes this by provision of flexible adjustable support means for the major portion of the length of the hose means which transmits the air and the water fromthe console 12 to the handpiece 18. As shownin the drawing, this flexible adjustable support menas comp i ses a gooseneck 16. However, it will be apparent that variations'from the specific structure shown may forlocating the handpiece 1s. .Thus, with the major portion of the hose supported in this manner, no drag will be caused upon the handpiece as a result of the weight of the hosing utilized.

Such adjustable support means cooperate witha suitable length of flaccid hose means 20 which extends between, the-end of the adjustable support means 16 and the handpiece 18. The length of theflaccid hose means 20 is of such a light and flexible nature that it creates minimal drag and torque effects upon the hand- I piece I8. The material chosen for the length of hose means 20 is of such a nature that little or'no resistance is developed to movement of the handpiece l8 and, accordingly, free and easy manipulation and location thereof during the performance of dental operations is enabled. The particular material and configuration of the hose means 20 will be described in greater detail hereinafter, but it should be apparent that in the performanceof work within the oral cavity, the dentist may first locate and adjust the gooseneck 16 to a location generally, within proximity of the point at which work is to be performed. This can be done with ease and facility, and as a result the major portion of the hose length will be appropriately located and completely supported by the gooseneck 16,. With the gooseneck lb appropriately located, the dentist may then easily t manipulatethe handpiece 18 in the vicinity of the oral cavity since, due to the nature and composition of the flaccid hosevmeans portion 20, a sufficient degree of movement appropriate to the performance of ordinary dental operations is accommodated.

The FIGS. lA'and 1B show alternative arrangements for'the dental apparatus shown in FIG. 1. In FIG. 1A

there is shown a console 12a having an articulated adjustable support member 28 extending therefrom in place of the gooseneck 16, of FIG. 1. A'shortened sec-, tion of a gooseneck extends between the articulated support 28 and the flaccid hose means 200 A dental handpiece 18a is connected to the flaccid hose means 20a in identically the same manner as is shown in FIG. l with the only difference between the structures of the FIGS. 1 and IA being that the gooseneck member 16 is somewhat shortened with portions thereof being replaced by the articulated member 28.

The articulated support member 28 comprises a pluralityfof rod members 30 joinedby a group of. pivotal joints 32 with the entire articulated assembly being expandable and adjustable to locate the handpiece -18a' proximate a working location. Of course, the gooseneck 16g will operate in generally the same manner as the articulated support 28 to provide adjustable supported positioning of the handpiece 18a. With the articulated support member -28 and the gooseneck 16a in place, the portions of hose means extending therethrough will be firmly supported in a desired position avoiding the occurrence of drag on the handpiece 18a.v Of course, the flaccid holsemea'ns 20a will operate in the same manner as described in connection with FIG. 1 to privide similar results eliminating torque. 40

FIG. 1B shows a secondalternative embodiment wherein the source of air and water is affixed to the rear of the dental chair 10. As shown, a unit 34 is at-- tached at the rear of the chair 10 and has extending therefrom a gooseneck 1611 containing therein appropriate hose elements to transmit air and water to the operating 'instrumentality of a handpiece 1 8b conne cted to the gooseneck 16b by flaccid hose means20b in much the same manner as previously described. It will be apparent that by mounting the power source 34 upon the back of the chair l0, closer proximity of the handpiece 18b to the patient may be achieved without unduly encumbering the workspace around the chair.

the gooserieckl6. Since the gooseneck 16 will fully support and maintain the length of the hose means contained therein in any desired position, no drag or weight effects upon the handpiece will be produced by thisportionof hose means. FIGKIC is an enlarged verof hose means sion of a portion of FIG. 1 showing the manner wherebythe hose means may be mounted and sup- 7 ported within the gooseneck 16. In the preferred embodiment of the present invention described herein, the hose means which extend within the gooseneck 16 are not comprised of the flaccid material utilized inthe formation of the hose means 20, but instead are configured to comprise a pair of ordinary hoses 40a and 40b formed of conventional material which operate to transmit air and water to the hose means 20.

The specific material utilized in the formation of the hose means 20 of the preferred embodiment described,

herein is a silicone rubber compound which. exhibits the desired characteristics giving rise to the benefits of the present invention. Such silicone rubber compounds are commercially available and may be obtained from the Dow Corning Corporation under the trademark Silastic.

Table 1 below sets forth data enabling a comparison between standard hoses-presently in use and the silicone hoses of the present invention.

*Maximum reaction torque with hose internal pressure at psi while in normal extended position.

As'will be seen from the above cited data, the hose torque produced upon the handpiece is significantly reduced by utilization of hose means of the present invention, represented by the three different samples identified as Silicone Hose Numbers 1, 2 and 3. It will be seen that, where hose arrangements previously known, i.e., Standard Hoses Numbers 1 and 2, will produce a torque on the hand piece of 45 or 50 gramcentimeters, the present invention enables reduction of this torque or drag to levels of between 2 and 8 gramcentimeters as indicated above. It should be understood that these readings were taken with the equipment in the normal operating position, but with no air thereby enabling greatly enhanced manipulability and heightened comfort and control during the 'performance of dental operations.

With the handpiece 18 alleviated of reactive torque and drag in the manner described, means may be effec .tively provided whereby the balance and feel of the handpiece may be varied and adjusted to suit the' preferance, of different operators as well as to enable the instrument to be more readily, precisely and'comfortably handled. By a second aspect of the present in-- vention, a weight is'providedwithin the handpiece,

- together with means for adjusting the positionof the or water flow through the hoses and with the internal hose pressure at 0 psi. However, it will be seen that little or no difference in the torque transmitted to the handpiece 18 will be realized with the hose means 20 under the normal operating pressure of about 32 psi since almost all of the torque or drag which is developed in hindering free manipulability of the handpiece 18 results from the stiffness and weight of the hose material and not from the operating pressures of the elements of the apparatus involved.

It has been found that the present invention enables the resistive forces produced upon a dental handpiece to be limited toiio iii ore than" l8 grain-centimeter;

Accordingly, it will be seen that with the arrangement of the present invention the handpiece 18 will be free of significant encumbering drag and torque forces weight relative to the handpiece, thereby to enable achievement of an individualized balanced feel. Such individualized adjustability is possible with heightened sensitivity in the feel of the handpiece due to the fact that the torque and drag forces, which would otherwise counteract the balancing force of such a weight, have been reduced or eliminated in the manner previously described.

A first embodiment of the present invention which provides an adjustable weight device'in the handpiece 18 is depicted in FIGS. 2-5. A weight member 50 is mounted within a housing 52 which also includes therein a worm 54 engaging the weight 50 along an internal worm gear threaded opening 56 for driving the weight 50 longitudinally along the interior of the handpiece'l8. A pairof end members 58 and 60 provide rotatable support for, the worm 54 within the housing 52, I with the member 60 also providing support together with a member 60a for a pair of gear shafts 62 andgt. Shafts 62 which rotatably mount a pair of spur gears 66 and 68 which are in engagement with the toothed interior of a control member 70 that has graduations marlred on the exterior'thereof. Con: trol member 70 is rotatably mounted upon the exterior of the handpiece 18 to enable controlled rotation of the spur gears 66 and 68. The worm 54 has affixed at one end thereof of a driven spur gear 72 which is engaged by -the sp'tir'gears 66 ar1d"6 8'for-rotation thereby to drive the worm 54 and thus effect positioning of the weight 50 along the length of the handpiece 18 by virture of the engagement of the worm gear54 with the threaded internal opening 56 in the weight 50.

' menitflsfi sthi smbsrflrssitien qatthe end oi t he handpiece 8, the weight 50 may be'adjusted to provide a-balanced feel for the handpiece which will be-suited to the particular desire'of an individual user. The weight 50'is provided with a pair of longit ifdinally extending circular openings 74 and 76 through which the hose means 21a and 21b extend. respectively, to enable sliding motion of the weight 50 along the length of the handpiece 18. v I

. The hose means 21a and 2 1 bwhich' extend internally of the handpiece 18 are preferably formed of metallic material and not from the flaccid material utilizedfor the hose means 20a and 2012, although they may be flaccid. As shown in FIGS, the hose means 20a and 20b a're fitted, respectivelyfover the ends of hose means 21a and 21b and are heldthere by a pressed fit or by any other appropriate means, such as the couplings 77 and 79. Since the hose means 214 and 21b are internally formed to be part of, and movable directly with, the handpiece 18, it will be apparent-that and with-little friction. Thus, when the worm S4 is I rotated it will operate to move the weight 50 longitue dinally along the hoses 21a and 21b which will act a tracking mechanism for the weight rotation thereof.

50 and obstruct The right end 'of. the housing 52 has formed thereuhousing 52 and servesvto'retain the hose means 21a and 21b. The member 70 is marked with graduated indicia on the outside thereof to indicate the relative position of the weight 50.

A second embodiment whereby weight means may be adjustably manipulated to alter the balanced feel of the handpiece is depicted in FIGS. 6, 7 and 8. A cylindrically shaped weight member 80 has its outer surface formed with spiral threads which engage the inner pon threads 61 which enables placement of an end cap 63 having internal threads engaging the threads 61 for mounting. An end sleeve 65 engages the end of the lation of the member 90. As the sleeve 84 is rotatably driven, its engagement with the weight 80 will operate to. position the weight 80 longitudinally within the housing 86 along the length of the handpiece 180 in much the same manner as was previously described in connection with thewei'ght 50. The hose means 20a and 20b may be supported in a manner similar to that described in connection with FIGS. 2-5 and similar in; tefheiheeemeene 21a and 2lb will operate as a tracking mechanism for the weight 30 which is prdvided wit'ha pair of cylindrical openings 97 and 98 formed inter-.

weight within a dental handpiece is shown in FIGS. 9, 7

9A and 10. ln this arrangement'a simplified manual approach' for adjustably moving the weight meanslis disclosed. A handpiece 18d includes an upper removable 7 .cover member99 which permits access to the head ofa screw member 104 adapted to threadably engage a weight member 100. The handpiece 18d includes a housing member 102 having a horizontal upper portion 103 whichfdefi nes a longitudinal slot 106 extending 'therealong. By loosening the screw 104 the weight 100 may be moved longitudinally along the handpiece 18d with the screw 104 sliding along the longitudinal slot 106as the weight member 100 is brought to a desired position. At this point, the screw 104 may be tightened to firmly engage the housing portion 103 between the upper surface 107 of the weight 1100 and the underside of the head of the screw 104. After appropriateadjustv merit of the location of the weight 100, the cover member 99 may be replaced and the handpiece 18d will be ready for utilization in the usual manner with the location of the weight 100 providing the individual ized balanced feel desired by the operator. 1 An additional alternative embodiment to the weight mounting arrangements previously described is shown in FIGS. 11 and 12. A weight 110is slidably mounted within a housing 1 18 of a handpiece 18, a portion only thereof being shown in FIG, '11. A removable cover member 112 overlies a horizontal upper portion 119 of the housing 118 and permits access to a stud member 114 having a spring 116 in cooperative relationship therewith and maintained in compression between the underside or portion 1 19 and a foot element 1 15 of the stud 114.'The stud 114 comprises a head member 117 which preferably has a serrated underside 124. The portion 119 defines a longitudinally extendingslot 120 through which. the stud 114 extends, with a serrated surface 122 preferably being provided on the upper side of the portion 119 located on either side of the slot 120 in a manner to engage the underside of the head' foot 115 to effect engagementof the undersurface 124 i may be effected by those skilled in the art without deof head 117 with the serrated surface 122 of the portion 119. Accordingly, the weight will be firmly held inthe desired location bythe interengagement of the serrated surfaces 122 and 124 which is maintained in a firm manner by the operation of the spring 116.

The metallic hose means 21a and 2lb will extend through the weight 110 and besupported thereby in a manner similar to that previously described and will operate as a tracking mechanism for the weight .1 10

From the foregoing it will be apparentthat the handpiece 18.shown in FIG. 1; as well as any of the handpieces shown and described herein, may be' appropriately configured to comprise weight means adjustment as described herein. With the handpiece' al-f seen that by the combined operation of an arrangement including the gooseneck' l6 and the flaccid hose means t 20, with the adjustable balancing weightmeans included within the handpiece, there will be afforded'a dental apparatus of greatly superior manipu'lability'vwith;

significantly enhanced comfort and precision of control. i t

Although the present invention has been defined in connection with specific structural embodiments thereof, it is to be understood that many variationsand modifications of the structure shown and described parture from the spirit and scope of the invention;

What is claimed is:

I i 1. Dental apparatus comprising a handpiece including an operating instrumentality manipulable for location relative to an oral cavity, a source of fluid supply, hose means extending betweensaid source and said handpiece fof transmittirig fluid to effect operation of said operating instrumentality, said hose means comprising a flaccid portion adjacent said handpiece rendering said hose means substantially ineffectual to impart reactive torque to said handpiece during manipulation thereof, and adjustable support means for said hose means enabling selective supported positioning thereof relative to said oral cavity, said support ;means being operably unconnected with said handpiece and' terminating support of said hose means a distance therefrom to leave unsupported said flaccid dinal passage therein through which said weight is movable and having a longitudinal slot communicating with said passage, said screw extending through said slot and beingpperatively engageable with a portion of the handpiece adjacent said slot when in said tightened condition to clampingly hold said weight in a hose means portion between said support means and rubber tubing. 4. Dental apparatus according to claim 1 wherein:

said adjustable support means comprises flexible jointed metal tubing.

5. Dental apparatus according to claim 1 wherein said adjustable support means comprises a plurality of articulated metal tubes, and pivotable interconnecting means pivotally joining said metal tubes together at their ends.

6. Dental apparatus according to claim 1 comprising a weight movably mounted on said handpiece, and means for moving said weight relativeto said handpiece for effecting a desired balance of said handpiece when held by an operator. relative to 7. Dental apparatus according to claim 6 wherein said handpiece comprises a generally elongated configuration, and wherein said moving means comprise gear means engaging said weight and being'manipulable to drive said weight along the length of said handpiece to any one of a plurality of positions.

8. Dental apparatus according to claim 7 wherein said gear means comprise a worm extending longitudinally of said handpiece, gear thread means formed upon said weight and operably engaging said worm, means to obstruct relative rotation between said handpiece and said weight, and a control member manipulable to rotate said worm for effecting movement of said weight along said handpiece.

9. Dental apparatus according to claim 7 wherein said gear means comprise a sleeve member rotatably mounted upon said handpiece and having gear threads formed internally thereof, said weight comprising gear threads formed thereupon operably engaging said sleeve internal gear threads, means for obstructing relative rotation between said weight and said handpiece, and a control member manipulable to rotate said sleeve member thereby to drive said weight relative to said handpiece to a desired position.

10. Dental apparatus according to claim 6, wherein said moving means include a screw threadedly mounted in said weight for movement between a tightened and a loosened condition, said handpiece having a longitupreselected position, said screw and weight being movable in said slot and passage, respectively, when said screw is in said loosened condition.

11. Dental apparatus according to claim 6 wherein said moving means comprise spring means interposed between said weight and said handpiece, said handpiece and saidspring means having a pair of frictionally engageable confronting surfaces, said spring means being held between said weight and said handpiece to generate a spring force holding said confronting surfaces together, and being manipulable to release said spring force for enabling movement of said weight relative to said handpiece to a selected position with reengagement of said confronting surfaces by application of said spring force holding said weight in said selected position.

12. Dental apparatus according to claim 11 wherein said confronting surfaces are serrated.

'13. Dental apparatus according to claim 7 comprising portions of said hose means extending interiorally of said handpiece and being formed of rigid material and being in fluid conducting relationship with said flaccid hose means portion, said weight having passage means through which said rigid hose means extends for slidably mounting said weight thereon for longitudinal movement, said rigid hose means preventing relative rotation between said weight and said handpiece. I I W q 14. A dental handpiece comprising an elongated handle, motor means carriedby said handle for driving an operating instrumentality, a weight connected to said handle and movable longitudinally thereof for altering the balance thereof, and means for releasably holding said weight in a preselected position.

15. A dental handpiece according to claim 14 further comprising means for moving said weight longitu dinally of said handle.

16. A dental handpiece according to claim 15 wherein said moving means comprises gear means engaging said weight means for driving said weight along the length of said handle to any one of a plurality of different selected positions.

17. A dental handpiece according to claim 16 wherein said handle has a longitudinal-passage therein and said gear means comprises a worm extending longitudinally of said handle in said passage, gear thread means formed upon said weight, said weight being disposed within said passage with said gear thread means operably engaging said worm, means to obstruct relative rotation between said handle and said weight, and means for rotating said worm for effecting longitudinal movement of said weight along said handle.

18. A dental handpiece according to claim 16 wherein said weight moving means comprises a sleeve member rotatably mounted upon said handle and having gear threads formed internally thereof, said weight comprising gear threads formed thereupon operably engaging said sleeve internal gear threads, means for obstructing relative rotation between said weight and said handle, and means for rotating said sleeve member thereby to drive said weight relative to said handle to a desired position.

19. A dental handpiece according to claim 14 I wherein said holding means comprises screw means extending relative to said handpiece and threadedly engaging said weight for adjustment between'a tightened and a loosened position, said handle being formed to permit movement of said weight relative thereto when 1 said screw means" are in said loosened position, said handle also being operatively engageable frictionally between said screw means and said weight means for holding said weight in a selected position relative to said handle.

whereby to enable movement of said weight relative 20, A dental handpiece according to clairn' 14 wherein said holdingrmeans comprise spring means interposed between said weight and said handle, said handle having a pair of frictionally engageable confronting surfaces, said spring means being positioned between said weight and said handle for producing a spring force for holding said surfaces in frictional, en 

1. Dental apparatus comprising a handpiece including an operating instrumentality manipulable for location relative to an oral cavity, a source of fluid supply, hose means extending between said fluid source and said handpiece for transmitting fluid to effect operation of said operating instrumentality, said hose means comprising a flaccid portion adjacent said handpiece rendering said hose means substantially ineffectual to impart reactive torque to said handpiece during manipulation thereof, and adjustable support means for said hose means enabling selective supported positioning thereof relative to said oral cavity, said support means being operably unconnected with said handpiece and terminating support of said hose means a distance therefrom to leave unsupported said flaccid hose means portion between said support means and said handpiece.
 2. Dental apparatus according to claim 1 wherein the overall reactive force upon said handpiece resulting from the weight and stiffness of said hose means is less than 18 gram-centimeters.
 3. Dental apparatus according to claim 1 wherein said flaccid hose means portion is formed of silicone rubber tubing.
 4. Dental apparatus according to claim 1 wherein said adjustable support means comprises flexible jointed metal tubing.
 5. Dental apparatus according to claim 1 wherein said adjustable support means comprises a plurality of articulated metal tubes, and pivotable interconnecting means pivotally joining said metal tubes Together at their ends.
 6. Dental apparatus according to claim 1 comprising a weight movably mounted on said handpiece, and means for moving said weight relativeto said handpiece for effecting a desired balance of said handpiece when held by an operator. relative to
 7. Dental apparatus according to claim 6 wherein said handpiece comprises a generally elongated configuration and wherein said moving means comprise gear means engaging said weight and manipulable to drive said weight along the length of said handpiece to any one of a plurality of positions.
 8. Dental apparatus according to claim 7 wherein said gear means comprise a worm extending longitudinally of said handpiece, gear thread means formed upon said weight operably engaging said worm, means to obstruct relative rotation between said handpiece and said weight, and a control member manipulable to rotate said worm for effecting movement of said weight along said handpiece.
 9. Dental apparatus according to claim 7 wherein said gear means comprise a sleeve member rotatably mounted upon said handpiece and having gear threads formed internally thereof, said weight comprising gear threads formed thereupon operably engaging said sleeve internal gear threads, means for obstructing relative rotation between said weight and said handpiece, and a control member manipulable to rotate said sleeve member thereby to drive said weight relative to said handpiece to a desired position.
 10. Dental apparatus according to claim 6, wherein said moving means include a screw threadedly mounted in said weight between a tightened and a loosened condition, said handpiece having a longitudinal passage therein through which said weight is movable and having a longitudinal slot communicating with said passage, said screw extending through said slot and being operatively engageable with a portion of the handpiece adjacent said slot when in said tightened condition to clampingly hold said weight in a preselected position, said screw and weight being movable in said slot and passage, respectively, when said screw is in said loosened condition.
 11. Dental apparatus according to claim 6 wherein said moving means comprise spring means interposed between said weight and said handpiece, said handpiece and said spring means having a pair of frictionally engageable confronting surfaces, said spring means being held between said weight and said handpiece to generate a spring force holding said confronting surfaces together, and manipulable to release said spring force enabling movement of said weight relative to said handpiece to a selected position with reengagement of said confronting surfaces by application of said spring force holding said weight in said selected position.
 12. Dental apparatus according to claim 11 wherein said confronting surfaces are serrated.
 13. Dental apparatus according to claim 7 comprising portions of said hose means extending interiorally of said handpiece formed of rigid material and being in flow relationship with said flaccid hose means portion, said weight having passage means through which said rigid hose means extends for slidably mounting said weight thereon for longitudinal movement, said rigid hose means preventing relative rotation between said weight and said handpiece.
 14. A dental handpiece comprising an elongated handle, motor means carried by said handle for driving an operating instrumentality, a weight connected to said handle and movable longitudinally thereof for altering the balance thereof, and means for releasably holding said weight in a preselected position.
 15. A dental handpiece according to claim 14 further comprising means for moving said weight longitudinally of said handle.
 16. A dental handpiece according to claim 15 wherein said moving means comprises gear means engaging said weight means for driving said weight along the length of said handle to any one of a plurality of different selected positions.
 17. A dental handpiece according to claim 16 wherein said hAndle has a longitudinal passage therein and said gear means comprises a worm extending longitudinally of said handle in said passage, gear thread means formed upon said weight, said weight being disposed within said passage with said gear thread means operably engaging said worm, means to obstruct relative rotation between said handle and said weight, and means for rotating said worm for effecting longitudinal movement of said weight along said handle.
 18. A dental handpiece according to claim 16 wherein said weight moving means comprises a sleeve member rotatably mounted upon said handle and having gear threads formed internally thereof, said weight comprising gear threads formed thereupon operably engaging said sleeve internal gear threads, means for obstructing relative rotation between said weight and said handle, and means for rotating said sleeve member thereby to drive said weight relative to said handle to a desired position.
 19. A dental handpiece according to claim 14 wherein said holding means comprises screw means extending relative to said handpiece and threadedly engaging said weight for adjustment between a tightened and a loosened position, said handle being formed to permit movement of said weight relative thereto when said screw means are in said loosened position, said handle also being operatively engageable frictionally between said screw means and said weight means for holding said weight in a selected position relative to said handle.
 20. A dental handpiece according to claim 14 wherein said holding means comprise spring means interposed between said weight and said handle, said handle having a pair of frictionally engageable confronting surfaces, said spring means being positioned between said weight and said handle for producing a spring force for holding said surfaces in frictional engagement and manipulable to release said spring force, whereby to enable movement of said weight relative to said handle to a selected position.
 21. A dental handpiece according to claim 20, wherein said confronting surfaces are serrated. 